The invention is directed to removing unwanted constituents from a siliceous surface and determining the cleanliness of a siliceous surface.
Conventional window cleaning compositions are typically designed to leave no visible residue on a glass surface when used to clean the glass surface. In other words, the glass surface should be free from a film and streaking. To achieve these properties, the level of surfactant and other additives in the cleaning composition must be low.
Organic solvents are often present in conventional window cleaning compositions to enable the composition to remove common stains and oily contaminants from glass surfaces.
Some window cleaning compositions include hydrophilic polymers or long chain alkyl sulfate surfactants, which are alleged to impart water-sheeting and anti-spotting properties to a surface cleaned therewith. Such compositions tend to leave behind a hydrophilic residue, which contributes to the water-sheeting effect and helps to remove soil from the glass surface. However, hydrophilic residues do not help with the removal of stains imparted by markers and do not assist in the removal of oily residues.
Compositions that include silanes have been used to impart a hydrophilic property to a glass surface that has been cleaned and activated. The preference for some of these compositions is for the surface be activated immediately prior to, or simultaneously with, the application of the aqueous composition.
Coating compositions that include silanes have also been used to coat glass substrates to render them capable of being easily cleaned.